The present invention relates to a cutting tool insert having an internal microduct through which coolant flows to transfer heat away from the cutting edge and extend the useful life and productivity of the insert.
The cutting edge of a cutting tool contacts the work piece and performs the actual cutting. While in operation, a large quantity of heat is generated at the cutting edge. Prolonging the life of the cutting tool and operating the cutting tool at high speed requires cooling while the cutting tool is in operation, especially when the cutting tool is used to cut materials such as hardened steel, titanium, and nickel-based high-temperature alloys. A conventional method of cooling includes, for example, “flood” cooling, where a steady stream of coolant is splashed on the work piece and the cutting tool while in operation. This method of cooling is not very effective, as it provides indirect cooling of the cutting tool edge, as it is obstructed by the chip, and requires a relatively complex recycling system to salvage, filter, and reuse the excessive quantities of coolant used.
It is also known to flow a coolant through cooling conduits in a cutting tool insert. However, known assemblies employ conduits having cross-sectional dimensions on the milli-scale, and require relatively large flow rates of coolant. Because of their relatively large size, such known cooling conduits can only be positioned a certain distance from the rake face, flank face, and cutting edge without affecting the structural strength of the cutting tool insert. Such known cooling milliducts are focused on cooling the entire cutting tool insert, rather than focusing on transferring heat away from the cutting edge itself.